When a digital signature is applied to an electronic document, there is often a need to include a graphic appearance that will be displayed on the electronic document to indicate that a digital signature has been applied. The appearance is not strictly a part of the digital signature, but the appearance is closely linked to the digital signature and in many implementation is the appearance includes some feature that displays graphically the validity of the digital signature that is associated with it.
In many cases, users of digital signature software need to specify what types of information will be included in the appearance. Examples of information that might be included are without limitation, a raster image of a handwritten signature, a date of signing, a time of signing, and other similar information.
Once the graphic appearance has been specified, there is a need to indicate a location on the document where the appearance should be visible when the digital signature is applied to the document.
In some cases, there is a need to apply only a single digital signature and associated appearance to a document. In other cases, there is a need to apply multiple digital signatures and associated appearances to the document. In certain situation is, it is necessary to apply a single digital signature or multiple digital signatures to a document and to have the appearance associated with the Signature be duplicated on the same, location of every page of a multi-page document.
Prior art methods of specifying a digital signature appearance typically involve selecting item is such as, but not limited to, the signer's name, a digitized graphic, the date of signing, the time of signing, and the reason for signing, from a menu of choices. These items are then placed in the appearance by software in a location and at a scale that is determined automatically by the software. In prior art methods, the user does not control the size rotation, and placement of graphic elements in the appearance, or the font used for text such as date and time. In these prior art methods, the sizes of graphic elements that are included in the appearance are defined relative to one another only, and it is not possible to indicate a scale relative to graphic elements associated with an electronic document or a known paper size.
Prior art methods of specifying where the appearance associated with the digital signature should be located on the document typically involve indicating a window or bounding box into which the appearance will be scaled to fit. In some implementations this bounding box is drawn interactively by the user. In other implementation is the bounding box may be created in advance, and then it is selected by the user as the location for his or her signature appearance to be placed.
In these prior art methods, the size and location of the appearance associated with the signature on the document can be indicated only approximately. When the user draws a bounding box or selects a previously created bounding box for the appearance, the appearance is scaled to lit within this bounding, box, and the appearance may or may not be the correct scale relative to or aligned with graphic elements in the electronic document as desired by the user.
There are two prior art methods of indicating that a signature appearance should be displayed in the same location on every page. The first method is to apply multiple individual signatures, each one with an appearance on a different page. Typically this is done by creating a bounding box on each page or by selecting a previously created bounding box on each page. This method is time consuming, as the user must specify repeatedly that where the appearance should be located. This method often creates large electronic document files as well, as there is a certain amount of overhead associated with each digital signature, and often or hundreds of signatures are applied to a document, the electronic document may become unmanageably large.
The second prior-art method is for the user to create a bounding box for a digital signature appearance, but not yet create a digital signature associated with the box. In a second step, the user duplicates this bounding box on multiple pages of the document. In a third step, the user selects one of these duplicated bounding boxes and indicates that all the duplicated bounding boxes are to receive the same digital signature appearance. This method has the result of creating only one digital signature (and thus a smaller file size) but multiple instances of the appearance associated with this signature. This method involves at least three discrete steps, however, and is therefore time-consuming.
In view of the foregoing, there is a need for an improved method of composing a customized graphical appearance associated with a digital signature and applying that appearance to a desired range of-pages in an electronic document in a way that allows the user to specify the scale and location of the appearance on the electronic document and that is less time conuming and creates smaller electronic files than current methods
Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.